Leaded motor fuel containing boron compounds



United States Patent "LEADED MOTOR FUEL CONTAINING BORON COMPOUNDS Samuel M. Darling and Philip S. Fay, Lyndhurst, and Lorraine S. Szabo, Cleveland, Ohio, assignors to The Standard Oil Company, Cleveland, Ohio, :1 corporation of Ohio No Drawing. Application October 15, 1954, Serial No. 462,602

12 Claims. (CI. 44-63) This invention relates to a liquid leaded motor fuel comprising an organic boron compound incorporated therein in stable form.

It is well known that during the operation of an initially clean internal combustion engine, deposits form progressively and accumulate on the surfaces within the combustion zone, i. e., on the cylinder head, piston top, spark plug, and the intake and exhaust valves. As the operation continues, the amount of the deposits reaches a level after which there is no appreciable further increase in the amount of the deposits. The engine is then regarded as having deposit equilibrium and old deposits flake off as fast as new deposits form.

The deposit problem is aggravated when tetraethyl lead is contained in the fuel because the deposits are then no longer essentially carbonaceous, but comprise appreciable quantities of lead and lead compounds generally mixed in with the carbonaceous materail. Despite the fact that one or more organic halides are included in the fuel with the tetraethyl lead to serve as a scavenging agent, not all of the lead is removed. A carbonaceous deposit with lead is often more tenacious and troublesome than a pure carbonaceous deposit. The fact that this deposit is partially metallic in character is thought to give it a catalytic activity which modifies the action of the deposit in affecting engine operation. since the lead is intimately mixed in with the carbonaceous material, the lead in the deposit is difiicult to reach by means of scavengers or material reactive therewith to eliminate or modify it, especially in engines which have been in operation and which have such deposits built up in them over a long period of time.

These deposits have a number of adverse eifects upon engine operation, but with available fuels they cannot be avoided and are inherent in present day operation of internal combustion engines One adverse eflect of the deposits is manifested most clearly to the operator of the engine, particularly an automobile engine, by the fact that the presence of the deposits in the engine requires a fuel having a higher octane rating in order not to knock than is required by a new or clean engine. This requirement for a fuel of higher octane number, as the engine becomes progressively dirtier, persists until the deposits reach equilibrium, and is known as octane requirement increase (R1). Another factor to be considered is the reduction in the volume of the combustion zone equivalent to the volume of the deposits and the consequent increase in compression ratio which aggravates the above manifestation.

Another adverse eifect of the deposits is characterized by uncontrolled ignition, either pre-ignition or pos ignition. This is explained by the fact that the deposits, or portions of them become heated to incandescence and ignite the hydrocarbon either before or after the portion in the cycle at which the charge would be ignited by the spark of the spark plug. This manifests itself in various ways characterized as roughness," rumble, various Furthermore,

forms of knocking, and a general lack of smoothness in engine operation.

Another adverse effect of the deposits is on the spark plug, particularly when the deposits contain lead which results in spark plug fouling with resultant loss in power or reduced spark plug life.

Still another adverse elfect of the deposits is the result of their thermal insulating property. They are poorer conductors than the metal parts of the engine and as a result they interfere with proper cooling and temperature maintenance of the engine parts. This is particularly true in the case of the exhaust valves which become overheated and burn or otherwise deteriorate as the result of the deposits. A serious adverse effect of the deposits is the channeling of exhaust valves. This is explained by the fact that the deposits flake ch as fast as they are formed once the deposit equilibrium is reached, and the flakes leave through the exhaust valves. The glowing deposits exiting from the muflier have been seen by all who drive at night. As these deposits leave through the exhaust valve they may lodge between the valve and the seat, thereby interferring with the proper closing of the valve. The hot exhaust gases passing between the valve and the seat result in channeling. Failure of the valve to seal the combustion chamber properly results in loss of acceleration, power and mileage. Somewhat analogous results occur in connection with the inlet valves, but because these valves are cooler the character of the deposits is often different, and while not as severe, is nevertheless a problem in engine operation. The action of fuel and the deposits on valve life and condition has been largely overlooked or minimized in evaluating fuels, and since the valve action is vital to proper engine operation, this phase of the matter deserves special attention.

it has been proposed heretofore to add numerous compounds to fuel for the purpose of overcoming at least some of the above adverse effects. For example, in Patent No. 2,151,432 organic compounds of a large number of metals and non-metals are proposed for inclusion in fuel in a small amount to increase the efficiency of the combustion in an internal combustion engine. The compounds preferred in this patent are the. beta-diketone derivatives. It is pointed out in the patent, however, that boron, along with several other elements, does not form suficiently stable beta-diketones to be satisfactory for use in motor fuels, and therefore other compounds of boron and similar elements must be employed, such as tri-amyl boron and tri-isobutyl borate. Experience has shown that even these compounds are unsatisfactory, the first being a borine which has been found to be subject to oxidation, and the second being an ester of an aliphatic monohydric alcohol which is gradually hydrolyzable upon contact with water to preciptate boric acid which is insoluble in the hydrocarbon fuel. While this patent mentions the concept of organic boron compounds in fuelalong with compounds of a host of other elements-it fails to disclose a form of boron compounds that is suiliciently stable under all of the various manufacturing, storage and use conditions to assure that the organic boron compound will remain in the fuel and will arrive in the proper form with the fuel in the combustion zone to be eifective.

In a paper published in industrial Engineering Chem istry, volume 43, pages 28414 (December 1951), of which one of us is an author, there is disclosed the eifect of including certain organic boron compounds in gaso-' line. The compounds there disclosed are the norates of, aliphatic monohydric alcohols, the borines and boranes they leave almost everything to be desired for use in large scale manufacturing and marketing operations which are characteristic of the petroleum industry today. In these operations the gasoline is often manufactured ahead of use and placed in storage where there is an opportunity for the boron compound to oxidize, hydrolyze or otherwise become altered to a form in which it is no longer soluble in the gasoline, at least in the proportions in which it was originally present. This is particularly true of componnds'which are subject to hydrolysis since gasoline is often kept in storage tanksat bulk plants, in filling stations and in individual cars, all of which often contain small amounts of water at the bottom thereof. This contact of the gasoline with water gradually results in the hydrolysis of the boron compound with the formation of boric acid and the precipitation thereof to the aqueous phase where it is no longer effective in the fuel. Desirable as these compounds may be as far as engine operation is concerned, they are simply impractical for use commercially and it is impossible to use them to benefit the average motorist.

Another unique problem in connection with the incorportion of organic boron compounds in hydrocarbon fuel is concerned with the relation of hydrolysis or other forms of decomposition to molecular weight. In the boron compounds mentioned in Patent No. 2,151,432, which are of relatively low molecular weight, the boron comprises a substantial Weight percentage of the compounds. For this reason they can'be incorporated in the fuel in reasonably small amounts and still give an adequate boron concentration in the fuel. Peculiarly enough, however, these lower molecular weight compounds as a class are the most readily attacked by water and other 'decomposive forces. it is recognized that there are certain very stable organic boron compounds, but these are high molecular weight compounds of little boron content so that for the incorporation of a given amount of boron in fuel, such large quantities of the compound are required as to make their use uneconomic and thus unavailable to the motorist.

Inaddition to meeting the above criteria it is essential that the boron compound have such characteristics as solubility, volatility and chemical structure as to make it soluble in the fuel, and efiective in the combustion chamber.

It is an object of the present invention to provide a fuel containing tetraethyl lead, together with organic compounds of boron of the type hereinafter specified which are satisfactorily stable under present day commercial conditions of manufacture, storage and use of the fuel, and which contain a suificient amount of boron to be economic in their use for desirable results in engine operation; it is a further object of the invention to provide a fuel as herein described in which the boron compound is effective in modifying the action of the fuel in the engine, probably most likely through alteration of the amount or the chemical and physical nature of the deposits, so that the above adverse effects are eliminated or markedly reduced.

The boron compounds which may be employed in the fuel of the invention to meet the above objects may be characterized as having the following'general formula:

where R is an alpha or beta alkylene radical having-from 3 to 20 carbon atoms and where X represents hydrogen, or

The compounds used in the fuel of the invention may be made by reacting orthoboric acid with the corresponding alpha glycol having the formula HO-fi'i-{J-OE or the beta glycol having the formula HO-('t-(-dyJ-OH in which formulas the unattached valences are linked to hydrogen or to the straight chain or branched alkyl radicals to provide a total of 3 to carbon atoms in the glycol. The materials are reacted at mildly elevated temperatures. The water of reaction, or at least a part of it, is preferably removed, but apart or all of the water of reaction may remain in the reaction mixture if it is dispersed in the gasoline such as with an alcohol or other mutual solvent. When the water is removed it is preferably separated overhead, such as by blowing with nitrogen or by distillation. All of the water can be removed by simple boiling. However, because of the low boiling point of many or" the compounds a certain amount may be lost due to volatilization during the removal of water. For this reason the complete removal of water may not be preferable unless it is done by means of fractional distillation or azeotropic fractional distillation, which permits the removal of the water with a'minimum loss of the reaction product. The reaction proceeds readily. Preparation of the compounds will be better understood in connection with the following example in which the glycol is 2-methyl, 2,4-pentanediol, but which is typical of the reaction with other glycols.

Example 1 A crystalline product was recrystallized twice from straight-run naphtha (a hydrocarbon having a boiling range of 43 to 127 C.) and once fromnormal heptane.

The product was a white crystalline solid and had a melt-- to 5 grams in 100 grams of gasoline, depending upon the 7 composition of the latter, all as measured at 86 F.

The compounds was analyzed and found to have the following composition:

Found by Calculated Analysis Percent Carbon Percent Hydrogen Percent Boron Molecular Weight 5 a. el -asap tux-1o wr-n- The boron determination was made by titration in the presence of mannitol, and the molecular weight is done cryoscopically in benzene. Infra red analysis confirmed the presence of the hydroxyl group, and repetition under conditions permitting recovery of the water of reaction showed that two moles of water were formed.

Example 2 49.5 grams of dry orthoboric acid and 94.5 grams of Z-methyl, 2,4-pentanediol (a 1:1 molar ratio) were mixed together. Upon mixing, the temperature dropped approximately 8 to 10 C., and upon additional stirring, the temperature then rose rapidly to and slightly above the initial temperature, at which time the mixture became solid. The mixture was then heated and became completely liquid at about 70 to C. cc. of benzene was added and the water formed was removed azeotropically by distillation with the benzene over a period of several hours. The reaction proceeds in accordance with the following equation:

2 B-OH and the product may be named bis-(1,1,3-tn'methylt'rimethyleneoxy) boric oxide. The compound of this example was found to be a colorless liquid of medium viscosity. It is miscible in hydrocarbons, and particularly in gasoline, and the common organic solvents in all proportions. It has the following additional properties:

Boiling point Approximately 275 C. at atmospheric pressure and -142" C. at 1 mm. Hg.

Molecular weight Calculated 269.9, found 246.5.

Per cent boron Calculated 8.01, found 7.41.

The boron determination was made by titration with mannitol, and the molecular weight was done cryoscopically in benzene. Infra red analysis confirmed the absence of the hydroxyl group, and repetition under conditions permitting recovery of the water of reaction showed that two and one-half moles of water were formed for each mole of glycol and boric acid reacting.

The above compound was twice distilled at a pressure ant-,0

. r less than Hg. The narrow boiling heart out was. submitted to analysis. The following composition was found:

Found by Calculated Analysis Percent Carbon 5s. 39 53. 42 Percent Hydrogen 8. 96 9. 02 Percent-Boron 8. 01 7. 79

The liquid anhydride product is very .hydroscopic and readily reacts with water to form the compound of Example l'. The anhydride of this example can also be prepared by dehydrating the compound of Example 1 by heating or desiccation. This reversible reaction is represented by the following equation When Example 2 was repeated employing the. glycol and boric acid in the ratio of 3:2, the product was a colorless liquid having the formula The compound had the following properties:

52 grams pentanediol-2,4 is reacted with 31 grams of dry orthoboric acid under conditions the same as that in the previous example. The product was a clear, colorless, viscous liquid having a boiling point of 114 C. at

1mm. Hg. It has the formula The yield was 61 grams which was vacuum distilled at 1 mm. Hg togive a yield of 55.8 grams. The compound reacts with water to give a product that is crystalline solid, havinga melting point of 76 C. and which has the formula 5 Example 5 40 g. of Z-ethyl, zabutyl-propanediol 1,3 and 10.5 g. of boric acid were heated. in. 25.0 ml. of benzene. The molar glycol to, boric acid ratio was 1.5, The reaction mixture was heated for six hours. The azeotrope distilled at 71 6). 9 ml. of water was obtained in the distillation. The excess benzene was distilled oil at atmospheric pressure. The residue was blown with N2 to remove all the benzene; The product was a colorless viscous liquid. The yield was 40 g. Analysis showed 4.3 and 4.4% B. The calculated amount of boron was 4.5%. The product has the formula:

40 g. oi 2,2-dietl 1ylpropanediol 1,3 and 11 g. of boric acid were heated in 250 ml. of benzene (molar glycol to boric acid ratio 1.5). The water was removed as an azeotrope. The latter distilled at 71 C. 11 ml..ot water was obtained. The excess benzene was distilled 01f at atmospheric pressure. The product was a viscous light yellow liquid. Yield was 43 g. Analyses gave 4.6 and 4.8% for the boron content. Corresponding calculated value was 5.2%. The product has the formula:

Gasoline solutions containing up to 3 cc. per gallon of e raethy l a a d t h ch all or the, above nhyd de had been added in 3 amount to provide 0.002. to 0. boron were stored in open beakers in a humidity chamber for several months at 75 F. No crystals were formed, and n y o h gaso in be o e and e t m showed the boron content to be the same. No precipitation occurred when the samples were stored at l0 F. for severalmonths, and theboron content was the same efo e a d te the e Fuel containing the boron compound should be and is sufiiciently stable to be stored-in contact with moisture for three, months without loss of boron content (probably ecause the boron is in a cyc c ru t r a d n t nk d to carbon). This is not possible with the compounds of the prior art referred to above.

The gasoline base stocks to which the boron compounds are added may be any of those conventionally used in mak ng m r ga o in lsesqli e o us in an u m bile), but preferably should'be clean burning, for example, with a General "Motors sludge number not over 50. This would exclude large amounts of thermally cracked stocks and olefin polymers.

The gasoline of the invention also contains tetracthyl lead in amounts up to 6' cc., but usually from cc. per gallon, and a scavenging agent. The latter may be 1 theory of. ethylene dichloride and /2 theory of ethylene dibromide (the so-called motor mix or MM) or 1 theory of ethylene dibromide, the so-called aviation mix or Reference to MM and AM hereinafter is intended to refer to a gasoline containing the scavenging agent in the amount above recited. By theory is meant the stoichiometric'amountof the ethylene dihalidc for combination with all of the lead as lead halide. The AM is preferred since in combination with the boron compound may'varyand the amountis preferably expressed in-terms' of boron. Generally an amount of the compound to provide 0.002% by Weight of boron (based on the total fuel) is the smallest amount that will give any significant effect. Amounts between 0.035% and 0.008% by weight are preferred. Use of amounts in excess of 0.1% usually cannot be justified economically.

The fuel containing an amount of the compound of Example 1 to provide 0.004% boron was extensively tested. This compound was selected in order that all of the tests may be comparative. Reference hereinafter to Boron is intended to refer to a gasoline containing this compound in the above amount specified.

The base stock in all tests was the same, namely a mixture of straight run naphtha and catalytic distillate in the ratio of 1:3 with 3 cc. of tetraethyl lead per gallon to give an octane number of 94.

Two different scavenging agents were employed, namely the MM and AM as defined previously.

The gasolines containing boron gave a significant reduction in octane requirement increase, and this efiect of boron is described in the I. and E. Chem. article referred to previously. This property of boron in gasoline is not particularly important today in view of the high octane number gasolines generally available which satisfy the demands of most cars as far as octane number is concerned. For this reason the effect of the boron compound was evaluated more critically in other respects.

Inasmuch as the deposits in an engine are the cause of most of the difficulties, a test was devised to determine the amount of the deposits formed with gasoline of the invention as compared with the same gasoline not containing boron. In this test conditions were employed which encourage deposit formation, namely the mild or low duty use analogous to city driving. A Chevrolet engine was used, running on a cycle of one minute idle and five minutes at 2,000 R. P. M. at 11.8 brake horsepower. This light load and relatively low speed is similar to city driving interrupted by traffic light stops. The test was continued for 100 hours and the engine dismantled and the amount of deposit ascertained. All experimental conditions were the same except for the gasoline. The total combustion chamber deposits per engine in this test are expressed in grams and are as follows:

Scavenger Additive MM AM Boron 57. 6 57. 6 None 60. 67. 1

The amount of the deposit on the piston top was separately ascertained, with the following results:

S cavenger Additive MM AM Boron 29. 5 20. 9 None 34. 2 28. 3

The amount of the exhaust valve tulips was separately ascertained inasmuch as these deposits have an important bearing on the operation of the engine and the reduction in them is significant.

It will be noticed that the presence of boron gave a lower deposit when used with both scavengers, although the lowest deposits were obtained with the AM scavenger.

To determine theeffect of boron on pre-ignition and related manifestations, a high compression Oldsmobile engine having a compression ratio of 10:1 was employed. In some cars on the road today the compression ratio is so low as not to make pro-ignition a problem, but there is a trend to higher compression ratios, and many cars are troubled by pro-ignition. In this test the engine was run for 28 minutes under idling conditions, which would build up fresh deposits. Following this the engine was accelerated for two minutes under a load simulating climbing a hill. The number of wild pings was observed electronically and was counted, following which the ignition switch was turned off and the seconds noted that the car continued to run with the ignition off. During this running time the fuel was being ignited by the heat of the deposits. Also the number of wild pings were similarly counted during this after-running period. All conditions were the same for each test except the fuel. The results are as follows:

Wild Seconds of Wild Fuel Ping with After- Ping with Switch on running Switch off 44 137 37. 5 131 l' 12. 5 36.5 93. 5 AM plus Boron 0 27 63 From the above data it will be seen that boron improves the motor mix in every instance, although the aviation mix gives such good results with the switch on so as to leave little room for improvement. Even here boron improves the operation. The ability to eliminate wild ping by the combination of AM and boron is especially noteworthy.

The effects described above and the manifestations of deposits in the general field of pre-ignition are subtle in detection and expression. They are characterized as both audible and inaudible, with and without rumble. A general lack of smoothness in operation accompanies any of these manifestations which is difiicult to characterize quantitatively in figures. by persons comparing fuels with and without the boron compound, even in lower compression engines, noted an increase in smoothness of operation as one of the characteristics most readily noted by the motorist.

In a further test, four fuels, i. e., the same base with MM and AM, each with and without the boron, were subjected to a test on the Pennsylvania Turnpike, employing twelve 1954 model cars, two each of Ford, Buick Century, Oldsmobile 88, Chevrolet, Chrysler New Yorker, and Cadillac. Each car was run 10,000 miles on the same gasoline, and each car was run on two gasolines, and each gasoline was tested in each type of car for the same number of miles, to give a total of 240,000 miles. The test was set up statistically to eliminate variations between cars, the details of the method being given in Experimental Designs by Cochran and Cox, Section 11.51. The cars were examined before and after the 10,000 mile run on a single gasoline, The valves were replaced at the end of 10,000 miles. The cars were driven at a uniform 60 miles per hour and were driven 400 miles continuously each day with an intermediate stop for refueling. All conditions were the same except for the fuels. This was a heavy duty test in which the exhaust valves would be subject to the most strenuous operating conditions and which therefore were examined with care and will be considered first. The average final statistical ratings in grams of the deposits on the exhaust valve heads However, subjective appraisal avenue In this instance the boron seems to be more effective in reducing exhaust valve head deposit with AM.

In this instance the boron appears to be more effective with the MM, probably because the AM is already about as effective in reducing exhaust valve tulip deposits as is reasonable, to expect.

Another important observation from the standpoint of the operation of the car is valve channeling. Channels worn on the valve faces permit the fuel to be expelled through these channels during the compression stroke and to permit a part of the hot gases to be expelled during the power stroke, with a resultant loss in power and mileage. The extent of channeling is determined by removing all of the valves from the car and examining the number of degrees around the circumference of all of the valves of a single car that are channeled. The final statistical ratings.

' are as follows:

Degree of Fuel: valve channeling MM 134 MM plus boron 84 AM A 13 AM plus boron 15 Total Car Fuel Deposit 1H1 I 13. 2 olet plus Boron 1' Ford {AM plus 'Boron 15. 5

Similar improvements in cylinder head deposit weight were obtained.

Another factor that was noted is oil mileage, with the following results:

Miles perquart Fuel: of oil MM 1506 MM plus boron 1788 AM 2007 AM plus boron 1319- The addition of the boron compound significantly ime proves the oil mileage with theMM but not with the AM.

As indicative of the engine wear in operating on different gasolines, the cylinder bore was measured before and after-the test. Average statistical ratings were calculated and are listed'in the following table in which the increase in cylinder bore diameter is expressed in units of inches.

Cylinder bore Fuel a increase MM 6.27 MM plus boron 6.48 AM' f 4.24

AM plus boron 2.67

In this instance the boron does not reduce the wear in the case of MM but the increase is small. Boron significantly reduces wear in the case of AM, which is already much lower than MM.

Each car was measured for acceleration after being driven for 10,000 miles on a single gasoline and this acceleration was expressed in terms of the number of seconds it required a car to increase from 22 miles an hour to 60 miles an hour on the flat open road with full open throttle. A decrease in the amount of time shows that the car is able to develop greater power and shows a better mechanical condition of the car. The statistical results are as follows:

Time to accelerate,

Fuel: seconds MM 14.62 MM plus boron 14.56 AM 14.92 AM plus boron 14.70

From the above data it will be seen that the boron improves the ability of the car to accelerate with both scavenging agents. The improvement is most notable in the case of addition of AM to boron, although the final acceleration is not quite as good as the acceleration of MM without boron.

The mileage obtained by the various gasolines was noted, with the following results:

Fuel: Miles per gallon MM 15.87 MM plus boron 15.95 AM 16.01 AM plus boron 15.93

From the above data it will be seen that the addition of boron to MM increased the mileage but that this was not the case on the addition of boron to AM. However, the mileage of AM plus boron, which has all the advantages inherent in the use of AM, is superior to the use of MM alone, which is the fuel heretofore commercially'available to the motorist.

The spark plugs were examined at the end of the tests and no fouling was observed. The ability of the boron to increase acceleration and mileage shows that boron has an advantageous elfect on power output, and this may be attributed in part to inhibition of spark plug fouling From the above data it will be noted that in some instances boron coacts with the MM to give an improvement and inother cases it coacts with AM to give an improvement. The action is not always consistent. The scavenger to be selected will depend upon the items of improvement believed to. be the most important. It is believed thatthe factors in which boron improves AM are more important and that the, final results for this combination are more significant to the motorist. For this reason this combination is preferred, despite the greater cost of the AM scavenger. If one is to use AM as the best method of reducing valve channeling, the addition of boronthereto gives improvements in many respects over AM alone, such as in acceleration and engine wear.

In instances, however, where the manufacturer will not want to increase his cost by substituting AM for MM, the use of boron with MM will result in the many improvements noted in the data.

In addition, the cars driven on the Turnpike were examined for other properties, such as muffler deposits,

mufiier corrosion, inlet valve deposits, piston ring weight and) two large groups of employee cars. In these tests the MM with boron and AM without boron were not tested because these tests were run to evaluate a proposed substitution of AM plus boron as a new fuel to replace MM. Each employee did not know whether the fuel he was using was the regular fuel or the proposed new fuel. Because of the difiiculty of keeping accurate controls, details of the test are not included, but they showed in general an increase in mileage, less valve deposits, lower octane requirement, reduction in ring wear, and an increased alkalinity of oil after the equivalent of 1500 miles driving. Inasmuch as the employee did not know which fuel he was using, opinion surveys can be considered as valid, and these showed more comments favorable for the AM plus boron than for MM. In addition, a survey from many thousands of motorists showed that two out of three detected an immediate improvement upon changing from MM to AM plus boron. The most predominant improvement noted was a smoothness of operation, despite the fact that the octane number was the same.

We claim:

1. Gasoline to which has been added up to 6 cc. per gallon of tetraethyl lead and a halide scavenging agent, together with a compound having 3 to 25 carbon atoms and the following formula where X is selected from the group consisting of hydrogen,

and where any R is selected from the group consisting of alpha and beta alkylene radicals having 3 to 20 carbon atoms, the amount of said compound in the gasoline being equivalent to 0.002 to 0.1% by weight boron.

2. The gasoline of claim 1 in which the scavenging agent is one theory of ethylene dibromide per theory of tetraethyl lead.

3. Gasoline to which has been added up to 3 cc. per gallon tetraethyl lead and an ethylene dihalide scavenging agent, together with a compound of the formula where R is a beta alkylene radical having 3 to 20 carbon atoms, the amount of said compound in the gasoline being equivalent to 0.002 to 0.1% by weight of boron.

4. The gasoline of claim 3 in which the scavenging agent is one theory of ethylene dibromide per theory of tetraethyl lead.

5. Gasoline to which has been added up to 3 cc. per gallon tetraethyl lead and an ethylene dihalide scavenging agent, together with a compound of the formula where R is a beta alkylene radical having 3 to 20 carbon atoms, the amount of said compound in the gasoline being equivalent to 0.002 to 0.1% by weight of boron.

6. The gasoline of claim 5 in which the scavenging 14 agent is one theory of ethylene dibromide per theory of tetraethyl lead.

7. Gasoline to which has been added up to 3 cc. per gallon tetraethyl lead and an ethylene dihalide scavenging agent, together with a compound of the formula Where R is a beta alkylene radical having 3 to 20 carbon atoms, the amount of said compound in the gasoline being equivalent to 0.002 to 0.1% by weight of boron.

8. The gasoline of claim 7 in which the scavenging agent is one theory of ethylene dibromide per theory of tetraethyl lead.

9. Gasoline consisting essentially of a base stock of straight run naphtha and catalytic distillate, about 3 cc. of tetraethyl lead per gallon, about 1 theory of ethylene dibromide per theory of tetraethyl lead, and a compound having the formula B-OH where R is a beta alkylene radical having 3 to 10 carbon atoms and hydrogens attached to the intermediate carbon atom, said compound being in an amount to provide 0.002% to 0.008% on weight boron.

10. The gasoline of claim 9 in which the compound has the formula 1): b-o H2O B-OH 11. Gasoline to which has been added up to 6 cc. per gallon of tetraethyl lead and a halide scavenging agent, together with a compound having the formula the amount of said compound in the gasoline being equivalent to 0.002 to 0.1% by weight of boron.

References Cited in the file of this patent UNITED STATES PATENTS 2,151,432 Lyons et a1 Mar. 21, 1939 2,257,194 Rosen Sept. 30, 1941 2,312,208 Clayton et al Feb. 23, 1943 2,497,521 Trautman Feb. 14, 1950 FOREIGN PATENTS 722,537 Great Britain Jan. 26, 1955 

1. GASOLINE TO WHICH HAS BEEN ADDED UP TO 6 CC. PER GALLON OF TETRAETHYL LEAD AND A HALIDE SCAVENGING AGENT, TOGETHER WITH A COMPOUND HAVING 3 TO 25 CARBON ATOMS AND THE FOLLOWING FORMULA 